1 Samuel 23:6
"And it came to pass, when Abiathar the son of Ahimelech fled to David to Keilah, that he came down with an ephod in his hand."
Cross References (ranked by relevance)
1 Samuel 22:20
And one of the sons of Ahimelech the son of Ahitub, named Abiathar, escaped, and fled after David.
1 Samuel 14:18
And Saul said unto Ahiah, Bring hither the ark of God. For the ark of God was at that time with the children of Israel.
1 Samuel 14:3
And Ahiah, the son of Ahitub, Ichabod’s brother, the son of Phinehas, the son of Eli, the LORD’s priest in Shiloh, wearing an ephod. And the people knew not that Jonathan was gone.